The 4th July was one of the lowest tides of the year at Filey and the seashore birds were feasting on around a dozen  velvet swimming crabs (Necora puber)  that had been left stranded on the beach near Filey Brigg. Body parts littered the beach. Several other crabs had made it to the relative safety of some rocky overhangs where an edible crab and velvet swimmer were waiting things out until the tide returned.

Three butterfish were also exposed . They are  eaten by herring gulls. Butterfish (Pholis gunellus)  are around 10cm or so long with distinctive black spot markings. Sometimes it is possible to see black spots along the fins. These are flukes (a trematode parasite called  Cryptocotyle lingua ). When the butterfish are eaten by gulls the parasite passes into their guts, later into gull droppings infecting small marine snails called periwinkles; the parasite then emerges from the  periwinkles and penetrates the butterfish, completing the fluke’s life cycle.


Tagged with:

Leave a Reply

Your email address will not be published.

+ 3 = 9

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>